Preheat the oven to 350°F (175°C) and line a baking sheet or baking tray with parchment paper or lightly grease it with oil.
In a large bowl, combine the mashed bananas, melted butter, brown sugar and vanilla. Stir until well combined.
Add in the dry ingredients: the rolled oats, shredded coconut, cinnamon, and salt to the bowl. Mix all the ingredients together until evenly combined and a cookie dough-like consistency is achieved.
Drop spoonfuls of the cookie dough onto the prepared cookie sheet, leaving some space between each cookie.
Bake in the preheated oven for 20-25 minutes or until the edges turn golden brown.
Once baked, remove the oatmeal banana cookies from the oven and let them cool on the baking sheet for a few minutes, about 5-7 minutes. Then transfer them to a wire rack or cooling rack to cool completely.
